Authentic Supplication Number 46.

The Messenger of Allah ┬ásaid to Bilal after the Morning Prayer: “O’ Bilal tell me about the deed you have done in Islam which you hope to be most beneficial to you, for this night I have heard the rustling of your feet at hand in Heaven? Bilal said I have done no deed in Islam which I hope to be more beneficial to me than that I never purify myself a complete purification in any hour of neither day, nor night except that I would pray with that purity what Allah has written for me to pray.

‘Al-`Adawee said it was sound, and that it was reported by Muslim, page 13 of volume 16; ‘Al-Bukhari, pg. 14 of volume 11 of Fath Al-Baree; and ‘Ahmad, 2/333, 439.